You know that a spoof is in trouble when it’s not even as funny as its target. The “Twilight” movies would seem ripe for satire, but “Vampires Suck” is a botched job. All three installments of the series so far offer more giggles than this excruciatingly prolonged public-access-cable-quality sketch.

That doesn’t come as much of a surprise since it was made by the guys responsible for the dreadful “Movie” franchise that’s included the “Date,” “Epic” and “Disaster” titles. Actually this entry is more like Jason Friedberg and Aaron Selzer’s “Meet the Spartans,” which concentrated on one movie (“300”) and only occasionally threw lobs at others, rather than taking their usual smorgasbord approach. Here the bargain-basement Zucker brothers take on the first two “Twilight” pictures (“Eclipse” came too late to be included), recycling the plot with lots of puerile jokes, tasteless sight gags and cheap slapstick added. Just imagine how filmmakers capable of real wit might have done the job; then think of how somebody totally witless would do it, and you’ll have “Vampires Suck”—a title that itself indicates the level of humor of which Friedberg and Selzer are capable.

One always hesitates to call out the cast members trapped trying to wring laughs out of material like this—they all undergo enough humiliation as it is—but of the lead duo, Jenn Proske comes closer to matching her model, Kristen Stewart; but Stewart’s such a bad actress that it’s a dubious achievement. Matt Lanter isn’t emaciated enough to be a convincing substitute for Robert Pattinson, but his exaggerated swoons are a decent approximation. Chris Riggi, the Jacob clone, is reduced to running around on all fours and spouting a chintzy dime-store tail. Sad.

Still, the most degrading material is certainly given to Diedrich Bader, as Becca’s (i.e., Bella’s) clueless father. When an actor is forced to play against an inflatable rubber doll, the damage is irrevocable. The only person matching him is Ken Jeong, who has to do more gruesome Oriental shtick as the head vampire.

“Vampire Sucks” certainly didn’t cost much, and the technical crew, including cinematographer Shawn Maurer, are to be congratulated for getting as much bang as they do from the buck. A pity their efforts are in the service of a movie that only a middle-school underachiever could find even mildly amusing.